190 OF THE HEART, VESSELS 



and particulary, why the gills or the liings cannot he noii* 

 dfhed, though tlie whole mafs paifes through them, 



Secl. IV. 



' a^. ^ From the extremities of thefe feveral arteries the 

 Wootl is returned to the heart by veins '^hich in general re- 

 femble our vena portarum (^n) and venae cavae (o). 



26. When we examine thefe veins more accuratelv^ wc 

 find two venae cavae, a right and left one, equal in fize and 

 fimilar in fituation, communicating freely by their trunks in 

 the abdomen, and in other places. as in the heart, by their 

 branches. In both, the branches are much larger in theic 

 courfe than at their terminarions and they, belides, form con- 

 fiderable receptades of blood. For inflance, each of the ab- 

 dominai cavas has douhle the diameter of the cavas conjoined 

 at the head 5 and, under the place at which the two cavae com- 

 nmnicate, there is a large receptacle of blood covered by thc 

 ovarium in the female, and by the teftes in the male (/?). la 

 like manner , the hepatic veins between the liver and dia- 

 phragm form finufes, the diameter of which is ten times great- 

 er than that of their openings into the cav^ {q)^ 



2J* Upon the v/hole the join in the following manner. 

 The vehu from the tail, joining with the iliac vein, form ehc 

 bottom of the two vcnae covae Tab» II. 24, Then the veins 

 from the organs of urine and generation are added, 24. 2^» 

 At 26. xhQ two abdomi?ial cauae , which arecontiguous, com- 

 nmnicate freeiy with each other» At 27, above the diaphrag- 

 nie and behind cartilages, which refemble our clavicles, the 

 abdominal cavaejoinwith the veins,which refemble tliebranch- 

 cs o{ our fiiperior cava^ At 28 * 29, 30, veins from ihQ 



mufcles 



(w) Tab III. XX, Y, 2Z, aa, bb, c, d, c, £• 

 {oj Tab II, 

 (p) Tab. IX. 5. 

 Iq) Tab, II. 31. 



